1. Field of the Invention
The present invention relates to constant spark rate ignition systems which store a predetermined amount of energy for the generation of each spark independent o power supply variations.
2. Description of the Prior Art
Ignition exciters for gas turbines currently in use are predominantly simple capacitive discharge units. They consist of a free running saturable core inverter, a storage capacitor, a firing device (usually a gas filled diode) and a high tension transformer whose secondary supplies the energy to the ignition plug. No regulation is attempted for variation in power supply voltage which is common in battery systems to which gas turbine engines are connected.
Spark ignition exciters based upon inductive discharge are also known. In an inductive discharge system, a current is built up in the primary of a transformer which is interrupted by the open circuiting of the switch to generate each spark.
Ignition systems are known which compensate for variation in power supply voltage so that the energy stored per spark is constant irregardless of the variation in the supply voltage. See U.S. Pat. Nos. 3,666,989, 3,714,507, 3,731,143, 3,835,350 and 4,083,347.